Citizens' Surveillance Micro-network for the Mapping of PM_(2.5) in the City of Concón, Chile

Ernesto Gramsch ； Luis Morales ； Marcelo Baeza ； Cristian Ayala ； Cristian Soto ； José Neira ； Patricio Pérez ； Francisco Moreno

《Aerosol and Air Quality Research》 20卷2期 (2020/02) Pp. 358-368

https://doi.org/10.4209/aaqr.2019.04.0179

摘要

A micro-network of low-cost sensors has been built and deployed in the city of Concón with the purpose of informing the community about the air quality in their neighborhood. Currently, 10 active stations, which are installed in resident-owned houses and public spaces, measure PM_(10) and PM_(2.5), rain, temperature, humidity, and wind speed and direction and display this information via a mobile application. The particulate matter is measured with a Dylos monitor, and the collected data has been calibrated using a Beta Attenuation Mass monitor for PM_(2.5) located in the same city as where the low-cost monitors are deployed. The PM_(2.5) concentration is obtained through a linear equation that uses small and large particle counts from the Dylos monitor. Additional calibration has been performed using neural networks, resulting in a noticeable improvement. The data also show that calibrations performed in other cities cannot be applied to measurements taken in Concón. As noted in many other studies, the relative humidity strongly influences the particle count. For the months of June, July, and August, the hourly profiles reveal a prominent evening peak in downtown Concón but a less obvious increase at the other sites, indicating that wood burning (or a similar source) mainly occurs in downtown. The nearby oil refinery, Enap, does not seem to increase the concentration of particulate matter on average, but short-term PM_(2.5) events generated by the refinery have not yet been analyzed.

關鍵字

PM_(2.5) ； Low-cost sensor ； Micro-network ； Refinery